Sprocket inserts

[oceanobob]

Regarding a JD 450G w around 2700hrs. Sprocket showing obvious wear. Pins still in spec with a little egg shape. Rails look decent, also in spec. No bad rollers. Grouser pads pretty good. Might need to repair/rebuild the tensioners as one side leaks to a certain point after tightening with the grease but then in an hour or so is back to a little looser than desired.

Original plan was to turn the pins. The cost of this including fuel to drive there and back twice isn't too far from new import rails and most say the best plan is to run to failure. But what does this mean? Cause this would mean the sprocket will be soon to be skipping and jumping.

What about this idea: has anyone heard of sprocket inserts? These reportedly would weld into the teeth and maybe would allow all the items to last a little longer and then replace all the parts at once. Work demands for the machine have not resumed the pre 2007 levels. But on the other hand, the machine is fully paid for.

 

[Old Magnet]

Here is my last known source of sprocket liners.
Don't know if still in business or not, it's been awhile.

 

[Bls repair]

Just wondering how you would get insert to fit the amount wear you have on your sprocket compared to someone else’s sprocket?

 

[PEVO]

I've seen somewhere on this forum where a person was thinking same as you ...made inserts out of drill stem pipe and welded them in. Don't know how that worked out. They were not perfect but I think they worked...he let his chains beat the inserts into the ideal shape after a few hours running

 

[Bluox]

Regarding a JD 450G w around 2700hrs. Sprocket showing obvious wear. Pins still in spec with a little egg shape. Rails look decent, also in spec. No bad rollers. Grouser pads pretty good. Might need to repair/rebuild the tensioners as one side leaks to a certain point after tightening with the grease but then in an hour or so is back to a little looser than desired.

Original plan was to turn the pins. The cost of this including fuel to drive there and back twice isn't too far from new import rails and most say the best plan is to run to failure. But what does this mean? Cause this would mean the sprocket will be soon to be skipping and jumping.

What about this idea: has anyone heard of sprocket inserts? These reportedly would weld into the teeth and maybe would allow all the items to last a little longer and then replace all the parts at once. Work demands for the machine have not resumed the pre 2007 levels. But on the other hand, the machine is fully paid for.

Could you post a picture of your sprocket and idler?
Thanks
Bob

 

[RZucker]

I've seen somewhere on this forum where a person was thinking same as you ...made inserts out of drill stem pipe and welded them in. Don't know how that worked out. They were not perfect but I think they worked...he let his chains beat the inserts into the ideal shape after a few hours running

Saw a guy try this on an old 82-30 terex… It did not end well. His homebuilt inserts shelled out rapidly.

 

[oceanobob]

Will get some pics of dozer, it is on a jobsite that we arent working at the moment.

Called Pigeon Products, there is a polite message about a delay in response, will give it a week or two.

 

[repowerguy]

Sprockets for a 450 Deere really shouldn’t be that expensive to buy new, the labor to put in the liners will be enough to make new sprockets look possible. On a machine that size, you’ll probably have to break the track anyway to make room to work welding in inserts, so you’re almost there to putting in a sprocket.

 

[oceanobob]

As to swapping sprockets for new and fixing the tensioner rod and its seal, breaking the track is indeed the method. Was thinking the sprocket inserts would grow the diameter slightly and lengthen the pitch a little because have been told a new sprocket on an old seasoned chain makes the sprocket wear extremely rapidly.....which may be true. But if that sprocket with such a said short life adds some run time to the rails and pins - then that might be of benefit? My original plan was to rotate the pins - who knows, what with tariffs maybe that becomes applicable although it isn't so cost effective compared to new last time I checked the numbers. Run em to failure is the "new mantra".

My thinking is if an old engine is slated for a rebuild, why not fix the water pump and continue running it until that time to pull it out....could be a bad example but is all I could think of LOL.

 

[repowerguy]

What I tried to say was that the cost of inserts plus welding consumables plus the man hours labor to install them will add up quickly and may equal new or newish sprockets. I think they were the same for several models earlier, used takeoffs could be a possibility.

 

[oceanobob]

Appreciated. Guess I went on a mental tangent worrying about the pitch of that old chain being effectively longer and would that create super fast wear on that new sprocket . somehow got the idea the shells would 'grow' the pitch to be more like a worn chain (rails)?

 

[Welder Dave]

It was several years ago but I bought weld on sprocket rims for a 931B Cat and they were $125 each from Trek. I don't think there's any way you could do it any cheaper. I think the JD sprockets are easy to unbolt too so it would real easy to weld them in the flat position.

 

[alaskaforby4]

New sprockets for a 450G are $150 each

 

[TomA]

Appreciated. Guess I went on a mental tangent worrying about the pitch of that old chain being effectively longer and would that create super fast wear on that new sprocket . somehow got the idea the shells would 'grow' the pitch to be more like a worn chain (rails)?

I think this may well be the case. I know if the sprockets are worn the pitch is beyond spec and will likely tear up a new sprocket. Chains wear sprockets, sprockets don' t wear chains. I wonder if those inserts are still available.

 

[Tinkerer]

$135.00 plus shipping on ebay.
https://www.ebay.com/itm/New-John-D...+sprockets&_from=R40&rt=nc&_trksid=m570.l1313

 

[Theweldor]

I have seen those sprocket inserts years ago. Have never used them though for a couple of reasons.
The way a sprocket seems to wear is the flat between the teeth thins out. If you were to unfold that sprocket out so that is was a flat the length of the pitch is off. But how do you get a piece made that would fit basically an oblong wear spot so that it is properly supported when it is welded in and not depending on just the welds to support it. Also if you add an insert that is say 3/8 " thickness this is going to throw off you pitch diameter which will cause very rapid wear. Don't get me wrong I have had some sprockets water jetted out to fit the pitch of some very expensive and long chain. But you have to calculate the pitch diameter and then have the sprocket built to those dimensions.
I just don't see how it would be cost effective to mess with the old sprockets when new ones are so reasonably priced and it would be much less work to change them than to weld in those inserts.

 

[Bls repair]

Kinda what I was thinking . You said a lot better then me

 

[Theweldor]

I should have added that maybe I have just gotten spoiled working on high sprocket 8's and 9's. When an undercarriage is the north side of $90.000 a set off sprocket segments is immaterial to keep it running for another year until it is complete junk.

 

[Jonas302]

I should have added that maybe I have just gotten spoiled working on high sprocket 8's and 9's. When an undercarriage is the north side of $90.000 a set off sprocket segments is immaterial to keep it running for another year until it is complete junk.

Exactly right new sprockets wear faster but are so cheap compared to dumping the undercarriage before its time
Just don't let them be skipping and jumping

 

[John C.]

Most small dozers in this area wear out the bottoms at between 3,000 and 3,500 hours. On small dozers I haven't seen anything pencil out on doing anything but running the undercarriage to destruction. If you are running SALT track it doesn't stretch so the wear on the sprocket just goes down and not onto the tips of the teeth. The small Cat line uses thicker bushings designed to run until they leak oil. The recommendations for awhile was run the sprockets until the chains were at 65% worn and then change the sprockets. Last stuff I was around was just run to destruction. I have seen companies run two sets of chains on one set of idlers and rollers to maximize ROI.